Organotin stabilizers for polyvinylchloride

ABSTRACT

NOVEL ORGANOTIN COMPOUNDS ARE PROVIDED FOR USE WITH KNOWN ORGANOTIN PRESERVATIVES FOR VINYLCHLORIDE RESINS TO STABILIZE SYNTHETIC RESINS AGAINST DEGRADATION BY THERMAL OXIDATION, SAID COMPOUNDS HAVING THE FORMULA   R(4-X)-SN(-OOC-(CH2)Z-((R&#39;&#39;-)Y-1,4-PHENYLENE)-OH)X   WHEREIN R IS SELECTED FROM THE GROUP CONSISTING OF ALKYL OF FROM 1 TO 18 CARBON ATOMS, CYCLOALKYL, ARYL, AND BENZYL, R&#39;&#39; IS ALKYL OF FROM 1 TO 1I CARBON ATOMS, X AND Y EACH ARE INTEGERS OF FROM 1 TO 3 INCLUSIVE, AND Z IS AN INTEGER OF FROM 0 TO 2 INCLUSIVE, AT LEAST ONE R&#39;&#39; GROUP BEING ADJACENT TO -OH GROUP IN THE PHENOLIC GROUP, AND STABILIZED SYNTHETIC RESINS HAVING INCORPORATED THEREIN AN INHIBITING AMOUNT OF SAID ORGANOTIN COMPOUNDS.

United States Patent Int. Cl. cdsr 45/62 US. Cl. 260-4575 3 Claims ABSTRACT OF THE DISCLOSURE Novel organotin compounds are provided for use with known organotin preservatives for vinylchloride resins to stabilize synthetic resins against degradation by thermal oxidation, said compounds having the formula rmqsnuooowm 3-0111x wherein R is selected from the group consisting of alkyl of from 1 to 18 carbon atoms, cycloalkyl, aryl, and benzyl, R is alkyl of from 1 to 12 carbon atoms, x and y each are integers of from 1 to 3 inclusive, and z is an integer of from to 2 inclusive, at least one R group being adjacent to OH group in the phenolic group, and stabilized synthetic resins having incorporated therein an inhibiting amount of said organotin compounds.

This invention relates to novel organotin compounds, to the preparation of such compounds, and to synthetic resins stabilized with said organotin compounds, This application is a continuation-in-part of application Ser. No. 615,895, filed Feb. 14, 1967 now US. Pat. No. 3,511,- 803, issued May 5, 1970.

It is known that certain organic compounds may be added as antioxidants to synthetic resins which are subject to deterioration from heat. For example, phenols alkylated to protect phenolic groups, of relatively low molecular weight are used commonly as such antioxidants. However, these known antioxidants may be characterized by unsatisfactory stabilizing ability because of thermal decomposition, volatilization, and sublimation during the process of producing films, fibers, or other molded articles. In addition, poor compatibility of the antioxidants with synthetic resins may cause plating-out, blooming, or bleeding phenomenon.

According to the present invention, these adverse effects may be reduced or eliminated by employing a new class of organotin compounds as stabilizers.

It is an object of this invention to provide novel organotin compounds and methods of producing such compounds. A further object of this invention is to provide synthetic resins stabilized with one or more of these novel organotin compounds. Other objects will be apparent to those skilled in the art from the following description.

In accordance with certain of its aspects, the method of this invention for stabilizing synthetic resins against degradation by thermal oxidation comprises incorporating with said resin an inhibiting amount of a compound having the following formula ')y wherein R is selected from the group consisting of alkyl of from 1 to 18 carbon atoms, cycloalkyl, aryl, and benzyl, R is alkyl of from 1 to 12 carbon atoms, x and y are integers of from 1 to 3 inclusive, and z is an integer 3,591,551 Patented July 6, 1971 "Ice of from 0 to 2 inclusive, at least one R' group being adjacent to OH group in the phenolic group.

In accordance with certain aspects of this invention, organotin compounds included in Formula I may be prepared by heating a compound of the formula wherein R, z, and y are as defined above with a tri-, di-, or mono-organotin oxide (or alkoxide) in an inert solvent medium such as benzene, toluene, etc. Other compounds within the general Formula I may be prepared by heating an alkali metal salt of carboxylic acid of Formula a with an organotin halide in alcohol, benzene, or toluene, and

HOOC(CH removing the formed alkali metal halide from the reaction system.

The novel organotin compounds obtained of this invention may be colorless to light yellow, crystalline or non-crystalline substances, depending upon the R and R' radicals, and the value of x, y, and z in the general Formula I. The compounds may be soluble in those general organic solvents which have a boiling point in the range of 40 to 300 C., e.g., aromatic hydrocarbons, alcohols, ethers, esters, ketones, petroleum hydrocarbon, etc.

Typical examples of compounds of Formula I are:

(10) 34H, cially useful in the production of the synthetic resins I when these resins are molded or polymerized at a rela- (C11,) 2Sn(O0C(CH2)2 OH)2 tively high temperature. Often conventional stabilizers and antioxidants sublime from resins at temperatures CH3 abcgve 170 C., and the amount used must be increased wherein t Stands for tertiary to e effective. Said organotin compounds are also profit- The low volatility of these organotin compounds may able m that the efiects of a plurality. of Sald organotlil 9 be known in the following table designated as Table I pounds i i .already known Stablhzers are Synerglstlc m their stabilizing effects: said organotin compounds with Table I sulfur-containing compounds as a peroxide decomposer on polyolefin and said organotin compounds with dibutyl- Percent wei ht loss b heatm i Organotin compound: at l80 C. for 18 minute: tm dloctyltm compour-lds SL-wh as? for d1 1 4 9O butyltin ester maleates including dibutyltin b1s(butyl 2 maleate), dibutyltin bis(octyl maleate), dibutyltin bis- 3 (benzyl maleate), and dioctyltin ester maleates including 4 dioctyltin maleate, dioctyltin bis (butyl maleate), dioctyltin 5 'bis(octyl maleate), dioctyltin 'bis(benzyl maleate), metal- 6 110 soaps, or lead compounds as a vinyl chloride resin 7 stabilizer. 8 The synthetic resins which may be stabilized by the 9 method of this invention include ABS (acrylonitrilebutadiene-styrene) resins, acetal resins, fiuoroplastics, 2 1 1 2; 36'30 acrylic resins, alkyd resins, amino resins, urethane resins, y p ff epoxy resins, polyamide resins, polycarbonates, poly- These organoti antioxidants and stabilizers may be olefines, polystyrenes, vinyl chloride resins, synthetic combined with or incorporated into the synthetic resins rubbers, etc. in several ways. For instance, the organotin compound EXAMPLE 1 or mixture of compounds may be added to the synthetic resins prior to polymerization. After the addition of the Naugilt Point iWO Perceilt y Weight of dibutyltin-bisorganotin compound, the admixture may be polymerized (fly y y y P y p p and molded into films, fibers, or other articles. Alternaaforesaid Formula 2] as a antioxidant was added to tively, the organotin compound may be added to the polyvinyl chloride resin composition containing 2% by synthetic resin together with other additives such as welght of dibutyltin maleate as a stabilizer, and 2% by another stabilizer, an ultraviolet light absorber, a color- Weight of butyl stearate as a mold lubricant, and after i agent, a m ld l b i t t b mix e,g a ibb milling for 15 minutes on a mixing roll at surface temblender, a high-speed mixer, etc. after which the mixture perature of 160 C. the mixture was made into a sheet 1 may be molded into films, fibers, or other articles. thick- The Fileei Was then P in a G661 Oven at Only an inhibiting amount of organotin compound is 180 C. for 80 minutes for the heat stability test. The same required, Preferably, the amount of the organotin ta. tests for heat stablllty Were directed to a comparison sheet bilizers and antioxidants to be employed in the process of 40 Without e addition f an antioxidant, and one with this invention is in the range of 0.01% to 5% by weight by Weight of 2,6'd1-teTt1aTY buiyi Piieii01 as an antihased on the Weight f the synthetic resins, which will oxidant. In l1ke manner were such tests made for sheets vary depending upon th ki d f ld d a ti l d th with tri-basic lead sulphate in place of dibutyltin maleate manner in which the organotin compounds are added. as a stabilizer. This data is listed on the following table The organotin compounds of this invention are espefor the different combinations of stabilizing agents.

TABLE 11 Color after Stabilizer Antioxidant Initial color 40 minutes minutes Dibutyltin maleate None Light yellow Yellow Light brown.

Do- ZAhdI-t-hutyl-imethyl Colorless Light yellow Yellow.

eno Do Cci mpound of Formula 2 do Colorless Light yellow. Tri-basie lead sulphate None White Light yellow Brown.

Do- 2,6- ki1i-t-liuty1-$methy1 .do do Light brown.

p eno 5 Do Compound of Formula 2 .do White White. Diootyltin maleat None Light yell Light brown-. Brown. Do 2,6d11-t-bi11tyl4-methyl Colorless. Light yellow Yellow.

p 6110 Do Compound of Formula 2 do Colorless Light yellow. Dioctyltin b1s(butyl maleate) one Light yellow" Yellow Light brown.

D0. 2 6-Cg-t-b1utyl-4methyl Colorless Light yell0w Yellow.

I) eno Do- Compound oi Formula2 do Colorless Light yellow. Dloctyltin b1s(octyl maleate) None Light yellow.- Yellow Light brown.

Do- 2,6-gi-t-liutyl-4-methyl Colorless Light yellow Yellow.

p eno Do. Compound of Formula 2 do.. Colorless. Light yellow. Dloctyltin bis(benzyl maleate) None Light yellow Yellow... Light brown.

Do. 2,6 h11-t-1iutyl+methyl Colorless Light yellow. Yellow.

eno Do. C mponud of Formula 2 do Colorless Light yellow. Dibuty tm b1s(butyl maleate) None Light yellow Yellow Light brown,

D 2,6-gi-t-butyl4-methyl Colorless Light yellow Yellow.

p en Do Compound of Foimula2 ..do C l les Li ht ll Dibutyltin bis(octyl maleate N one Light yellow Ygliiiwfnu Light hi m t g. Do. 2,6-ldl-t-lfutyll-methyl Colorless Light yellow. Yellow.

P 6110 Do Compound of Formula 2 ..do Colorless Light yellow. Dibutyltin bis(benzyl maleate).-. None Light yell0w Yellow Light brown.

Do. 2,6 di-t-butyl+methyl Colorless Light yellow. Yellow.

pien Do. Compound of Formula 2 do Colorless. Light yellow.

EXAMPLE 2 The composition was injection molded into a disk by conventional method. In this case the polycarbonate com- A two-component synerglstlc antloxldatlofl 1111mme of position was exposed to heat at 260 C. for 10 minutes.

02% y Weight of f y -(fi- Y Y The disk obtained was colorless and transparent. For Y Y p y P P afomsald Formula 5 comparison, 'a disk of polycarbonate without any addiand 04% y Weight of dilaufylthiodipl'opionate was tives was prepared under similar conditions. The disk obadded to polyethylene, and after milling for minutes mi d was li ht b on a mixing roll at surface temperature of 180 C. the EXAMPLE 7 mixture was made into a sheet 1 mm. thick. The sheet Was then pressed at 130 C. to get even surface, and was put 10 One hundred parts of polyoxypropylene triol (GR-3025,

in a Geer oven at 140 C. for the heat stability test. Com- Mitsui Chem. Ind. Co., Ltd., Japan), parison sheets with the addition of a single antioxidant 0.35 part of stannous octoate (T-9, M & T Chemicals of dioctyltin-bis-(fi-3,S-di-tertiary butyl-4-hydroxy phenyl Inc.), propionate), and without any antioxidant were put to the 1.5 parts of surface activate agent (II-520, Union Carsame tests. Results are shown in Table III. bide Corporation),

TABLE III After- Antioxldant hours 100 hours 400 hours 600 hours None Cracked, racked Cracked and yellowed Cracked and yellowed. Dioctyltin-tbis-(fl-li,5-di-tertiary butyl-A-hydroxy-phenyl Not deter1orated Not deteriorated.. Not deteriorated Cracked.

pro 1011?. e DiQct yItin-biS-(B-B,5-di-tertiary-butyl thydroxy phenyl do do Not deteriorated.

propionate) and dilaurylthiodipropronate.

EXAMPLE 3 0.1 part of triethylenediamine (DABCO, Foundry Process & Chemical Company),

Propylene sheets were tested for heat stability as 1n 4.5 parts of Water, and

Example 2. Results are shown in Table IV.

TABLE IV Aiter Antioxidant 20 hours 100 hours 400 hours 600 hours None Cracked Cracked Cracked Cracked, Dloctyltin-bis-(B-3,fi-di-tertiary bntyl-t-hydroxy-phenyl propionate)... Not deteriorated-- Not deteriorated do Do. Dioctyltin-his-(fl-3,5-di-tertiary butyl-thydroxy phenyl propionate) .do ..do Not deteriorated" Not deteriorated.

and dilaurylthiodipropionate.

ABS resin containing 0.5% by weight of dibutyltin-bis- 0.08 to 0.8 part of dibenzyltin-bis-(,8-3,5-di-tertiary (3,5-di-tertiary buty1-4-hydroxy benzoate) [of aforesaid butyl-4-hydroxy phenyl propionate) Formula 4] as stabilizer was injection molded into a flat were mixed thorou ghly with gentle stirring, and 54.5 parts Plate 2 g y l q s gi of tolylene diisocyanate (80/20) added with vigorous Process Sal resm composl was Su We 6 0 agitation. When the mixture began to foam, it was poured at 39 for 6 g iz-g g a i '22: into a corrugated cardboard container. The foamed polyg or mmu es 1 urethane was then exposed to sunlight and weathering outresu o no lsco Ora doors, and the color of the foam was observed with the For purposes of comparison, a fiat plate of ABS resin result as follows. without the addition of any stabilizers, and a plate with TABLE V 0.5 by weight of 2,6-di-tertiary butyl phenol as stabilizer were tested for heat stability by the same procedure com antioxidant Exposedfr as above. The former become yellow immediately after (p 3days 7days injection molded, and became brown after 60 minutes in Yellow Yellowish brow a Geer oven. The latter was white immediately after in- 8 ye11ow Ligliggollow.

jection molded, and became light yellow after 30 minutes in a Geer oven, yellow after minutes, and brown after 90 minutes.

EXAMPLE 5 Although tlgis inventlion has been illlilistrated by refer- 60 ence to specl c examp es, numerous c anges and modibi53 5352; g agli igfiog 122332;; gh f f di f i p gf which clearly fall Within the scope of said Formula 4] as stabilizer was injection molded into t wgf g i i to those skilled m the a flat Plate by conventonal method (heat career of 180 1. A stabilized synthetic resin composition comprising C./5 minutes). The plate obtained was colorless and trans- Parent, and was not discolored after allowed to stand in 2 2 223X: $2 2232 zgg f i fi g 22 1 2 g gg a room for two years. A flat plate of polystyrene without formula p the addition of any stabilizer, which was prepared by the same procedure as above for comparison was clear light R S 000 CH yellow in color when molded, and turned yellow with l 4 markedly lowered transparency after allowed to stand in (R')v a room for two years wherein R is selected from the group consisting of alkyl of from 1 to 18 carbon atoms, cycloalkyl, aryl, and

EXAMPLE" 6 benzyl, R is alkyl of from 1 to 12 carbon atoms, x and y To polycarbonate was added 0.5 by weight of dieach are integers of from 1 to 3 inclusive, and z is an octyltin-bis-(3,S-di-tertiary butyl- 4-hydroxy benzoate). integer of from 0 to 2. inclusive, at least one R group 8 being adjacent to --OH group in the phenolic group, and References Cited an already known stabilizer selected from the group consisting of a dibutyltin salt of a half-ester of maleic acid, UNITED STATES PATENTS dioctyltin maleate and dioctyltin salts of a half-ester of 2,826,597 3/1958 PY maleic acid 5 3,167,532 1/1965 Leebrick 26045.75

2. A composition as recited in claim 1 in which. said dibutyltin carboxylates are selected from the group con- HOSEA TAYLOR Pnmary Examlnel' sisting of dibutyltin bis(butyl maleate), dibutyltin bis V, P, HOKE, A i t t E i (octyl maleate) and dibutyltin bis(benzyl maleate).

3. A composition as recited in claim 1 in which said 10 US. Cl. X.R dioctyltin carboxylates are selected from the group con- 26023; 252-400 sisting of dioctyltin maleate, dioctyltin bis(butyl maleate), dioctyltin bis(octyl maleate), and dioctyltin bis(benzyl maleate). 

